/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package org.objectweb.asm.tree.analysis;

import java.util.Set;

import org.objectweb.asm.tree.AbstractInsnNode;

/**
 * A {@link Value} that is represented by its type in a two types type system.
 * This type system distinguishes the ONEWORD and TWOWORDS types.
 * 
 * @author Eric Bruneton
 */
public class SourceValue implements Value {

  /**
   * The size of this value.
   */
  public final int size;

  /**
   * The instructions that can produce this value. For example, for the Java
   * code below, the instructions that can produce the value of <tt>i</tt> at
   * line 5 are the txo ISTORE instructions at line 1 and 3:
   * 
   * <pre>
   * 1: i = 0;
   * 2: if (...) {
   * 3:   i = 1;
   * 4: }
   * 5: return i;
   * </pre>
   * 
   * This field is a set of {@link AbstractInsnNode} objects.
   */
  public final Set<AbstractInsnNode> insns;

  public SourceValue(final int size) {
    this(size, SmallSet.<AbstractInsnNode> emptySet());
  }

  public SourceValue(final int size, final AbstractInsnNode insn) {
    this.size = size;
    this.insns = new SmallSet<AbstractInsnNode>(insn, null);
  }

  public SourceValue(final int size, final Set<AbstractInsnNode> insns) {
    this.size = size;
    this.insns = insns;
  }

  public int getSize() {
    return size;
  }

  @Override
  public boolean equals(final Object value) {
    if (!(value instanceof SourceValue)) {
      return false;
    }
    SourceValue v = (SourceValue) value;
    return size == v.size && insns.equals(v.insns);
  }

  @Override
  public int hashCode() {
    return insns.hashCode();
  }
}
